Crankcase ventilation indicators



Jan. 16, 1968 M. A. LO PRESTO CRANKCASE VENTILATION INDICATORS Filed April 5, 1965 INVENTOR MAI? T/N A. LOPRESTO A TTORNEY United States Patent 3,363,454 CRANKCASE VENTILATIGN INDICATORS Martin A. L0 Presto, 1301 Castiemount Ave, Apt. 2, San Jose, Calif. 95128 Filed Apr. 5, 1965, Ser. No. 445,633 4 Claims. (Cl. 73-116) ABSTRACT OF THE DISCLOSURE A pressure-sensitive device which measures the pressure adjacent the positive crankcase ventilation valve of an internal combination engine and thus indicates whether or not the crankcase ventilation system is functioning properly.

This invention relates to an internal combustion engine having a crankcase ventilation system for recirculating unburned hydrocarbons from a crankcase back to an intake manifold, and more particularly to an indicator for showing whether or not the crankcase ventilation system is functioning properly.

An internal combustion engine should have a crankcase ventilation system to clean blow-by vapors from the crankcase and to prevent the discharge of blow-by gases into the atmosphere. The need for positive crankcase ventilation has become acute in recent years because blow-by gases of internal combustion engines, as used in automobiles, have been entering the atmosphere and creating smog in densely populated areas. Some states have enacted laws requiring the installation of approved pollution control devices on motor vehicles. Such smog con trol devices have frequently proven to be unsatisfactory because of improper installation or as the result of having become clogged with carbon and sludge. Continued operation of an internal combustion engine, when the crankcase ventilation system is not functioning, can result in serious engine damage.

An object of the present invention is to provide an indicator so that an operator can determine whether or not a crankcase ventilation system is functioning properly while an internal combustion engine is running.

Another object of the invention is to determine when a smog control valve within a crankcase ventilation sys tem should be serviced.

A further object of the invention is to prevent damage to an internal combustion engine equipped with a crankcase ventilation system.

An additional object of the invention is to readily diagnose crankcase ventilation problems and thus maintain an internal combustion engine in efiicient operating condition.

Other objects and advantages of the invention will be apparent from the following detailed description, reference being made to the annexed drawing, in which:

FIG. 1 is a side elevation view of an internal com bustion engine having a crankcase ventilation system including a control valve, a coupling section and an indicator embodying the present invention.

FIG. 2 is a diagrammatic view of the indicator shown in FIG. 1 connected in a crankcase ventilation system.

FIG. 3 is a front elevation view of the indicator shown in FIG. 2.

With reference to FIG. 1, an internal combustion engine 16, of the type commonly used in automobiles, is shown having an intake manifold 12 with a carburetor 14 mounted thereon. An air filter housing 16 is mounted above the carburetor and air is taken into the air filter housing where it is cleaned and then passed to the car buretor for mixing with fuel such as gasoline, to form a combustible charge. The fuel mixture then passes through Patented Jan. 16, 1968 the intake manifold, into the internal combustion engine where it is burned. The internal combustion engine includes a lower crankcase portion 18 and a valve rocker arm cover. The crankcase ventilation system includes a conduit 22 connecting the crankcase in flow communication with the intake manifold. A control valve 24 is positioned within the conduit to prevent a reverse flow of gases from the intake manifold to the crankcase. A coupling section 22 is positioned within the conduit between the control valve and the crankcase. A tube 28 connects the coupling section in pressure sensitive communication with an indicator 30 for indicating whether or not the ventilating system is functioning properly.

The control valve 24 and the coupling section 26 are shown in section in FIG. 2. The control valve includes a housing 32 defining an axial passageway 34. A valve seat 36 is provided within the control valve housing adjacent the axial passageway. A check valve 38 is adapted to fit upon the valve seat and thus close the axial passageway. The check valve is resiliently maintained in position by a coil spring 40 interposed the check valve and the control valve housing opposite the valve seat. A coupling stem 42 defining the axial passageway extends downwardly from the valve seat and is adapted for connection with the coupling section 26. A connection stem 44 extends upwardly at the opposite end of the control valve housing and is adapted for connection with the conduit 22.

Coupling section 26 includes a body 46 defining a central flow passage 48 through which blow-by gases flow in the direction of arrow 50. A coupling stem 52 extends downwardly from the body 46 at the upstream end of the coupling section while the downstream end of the coupling section is adapted to receive coupling stem 42 of the control valve 24. A connection stem 54 extends transversely of the central flow passage and projects outwardly from the body. A pressure communication channel 56 is located within the connection stern and an opening 58 is provided between the channel and the central fiow passage 48 facing the control valve end of the body 46. Tube 28 connects with the outwardly extending portion of the connection stem 54 to link the channel 56 in pressure sensitive communication with the indicator 30.

The indicator 30 includes a housing 60 having a face opening 62 provided therein. A tubular channel 64 having outwardly extending legs 66 and 68 is positioned within the housing. The tubular channel includes a central portion 70 which is inclined in a vertical plane together with an upper end portion 72 and a lower end portion 74. Tube 28 connects leg 66 in pressure sensitive com-munication with the coupling section 26 while leg 68 is open to atmospheric pressure. A ball 76 is moveably positioned within the central portion of the tubular channel and is responsive to a normally operating vacuum maintained in the central fiow passage 48 so as to hold the ball at the upper end portion under normal operating conditions. Should the vacuum within flow passage 48 drop below the normal operating level, the ball will roll down the central portion 70 to the lower end portion 74. The ball is confined within the tubular channel 64 between the legs 66 and 68 because of restrictions at the points where legs bend outwardly therefrom. An indicator card 78 is positioned within the housing 60, as shown in FIG. 3, to indicate to an operator that when the ball is in the upper end portion 72, the ventilation system is clear but when the ball drops to the lower end portion 74 while the engine is operating, the system should be serviced. The card may be illuminated by a small light for night operation and the ball 76 may be of luminous material.

In operation, a crankcase ventilation system installed as previously described on an internal combustion engine 10 provides for the recirculation of unburned hydrocarbons from the lower crankcase portion 18 to the intake manifold 12. This recirculation flow is induced by the vacuum within the intake manifold. So long as the crankcase ventilation system is functioning properly, the vacuum pressure Within the central flow passage 48 will hold the ball 76 at the upper end portion 72 of the tubular channel 64. In the event that the control valve 24 becomes clogged with carbon and sludge or for various other reasons, the crankcase ventilation system fails to operate properly, the flow of blow-by gases through the ventilation system will be reduced and pressure will build up within the central flow passage 48. This increase in pressure will tend to equalize the pressure differential between the upper end portion 72 and the lower end portion 74 of the tubular channel 64. Gravity will tend to cause the ball to roll down the inclined central portion 70 of the tubular channel to the lower end portion. An operator of an internal combustion engine will readily note that when the ball is at the lower end portion and the engine is in operation, the crankcase ventilation system needs to be serviced. Thus faulty operation is readily diagnosed and costly engine repairs are prevented.

It will be understood that modifications and variations of the embodiments of the crankcase ventilation indicator disclosed herein can be resorted to without departing from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1 In a ventilating system for an internal combustion engine having a crankcase in which blow-by gases collect and an intake manifold through which said gases are recirculated tor burning, a conduit connecting said crankcase in flow communication with the intake manifold, a control valve positioned within the conduit to prevent a reverse flow of gases from the intake manifold to the crankcase, and indicator means connected to said conduit and being responsive to normal operating vacuum within said ventilating system to show whether or not the ventilating system is functioning properly.

2. In a ventilating system for an internal combustion engine having a crankcase in which blowby gases collect and an intake manifold through which said gases are recirculated for burning,

a conduit connecting said crankcase in flow communication With the intake manifold,

a control valve positioned within the conduit to prevent a reverse flow of gases from the intake manifold to the crankcase,

a coupling section positioned within the conduit between said crankcase and said control valve,

a tube connected to said coupling section in pressure sensitive communication and an indicator connected to said tube being responsive to pressure variations for indicating whether or not the ventilating system is functioning properly.

3. The combination described in claim 2 which includes an indicator having a tubular channel inclined in a vertical plane and having an upper end portion and a lower end portion,

said tube connecting the upper end portion in pressure sensitive communication with said coupling section,

said lower end portion being open to atmospheric pressure and a ball movably positioned within the tubular channel being responsive to a normal operating vacuum maintained in said coupling section so as to move to said upper end portion but when said vacuum drops below said normal operating level, said ball Will roll to said lower end portion.

4. The combination described in claim 2 which in cludes a coupling section having a body defining a tlow passage for blow-by gases and having one end adapted for connection to said control valve while the opposite end is adapted for connection to said conduit and a connection stem extending transversely of said flow passage and projecting outwardly from the tubular body defining a pressure communication channel,

said stem having an opening of the pressure communication channel positioned within said flow passage facing the end of said tubular housing to which said control valve is connected,

said stern extending outwardly from said tubular body and being adapted for connection with said tube so as to provide pressure sensitive communication therewith.

References Cited UNITED STATES PATENTS 1,323,048 11/1919 Goodwin. 1,729,732 10/1929 VVasson. 1,965,333 7/1934 Connell 73-209 2,970,561 2/1961 Ashwood 116-117 FOREIGN PATENTS 89,106 11/1895 Germany.

RICHARD C. QUEISSER, Primary Examiner.

JAMES J. GlLL, Examiner.

' J. W. MYRACLE, Assistant Examiner. 

